five20too

Ok so I just bought this 95 1-ton from a guy in Ohio. It has a good bit of rust on it so I decided to undercoat my truck so I don't stick out like a sore thumb down here in Texas. I have done my research on the many posts and have narrowed it down to two different products. One of them I was previously decided on after reading about it in Diesel Power. They used the SEM products. I thought it turned out real nice but my friend recommended I check out POR 15. I did and they are also real convincing. The only thing that I like about the SEM method is the use of a rust neutralizer and then the undercoat. Please chime in if you have had experience with either or both and let me know how it worked for you. Thanks.

dkenny

no experience, but in the same boat..lots of rust on my diesel dodge from DE..

LOTS of RUST.. I wish I have the time and money to sandblast everything and start over..

I have heard good things about por15..for different uses..think trailers used in salt water..with good results..

-dkenny

CTD2001

are you just looking to cover up the rust on the underneath of the truck? Frame and axles ect? What i do each spring and fall before winter starts is get the underside real clean, free and any sand and residual salt and then i get out a steel brush and bursh the heck out of everything and get all the rust flakes removed, once i do that i just lay on a few coats of regualer old black gloss spray paint under the entire underside of the truck. When done, it looks just like it rolled off the showroom floor again, and if your religous about it the rust stays at bay beacause the paint protects/stops it. I got 130K on my truck and my fathers got 240K on his truck and both of them looks just as new underneath as the day they were purchased. I use about 5 cans of paint each time i do it. If only we could keep the body pannels from bubbling up with rust in spots. Just and idea

five20too

That is a good idea CTD2001. And I figure since I'm down here in Texas it won't really need to be done every year since we don't have all of that sand and salt. I may give that a try and see how it turns out. If I don't like it I guess I could always do the POR 15 over it.

Robert Rausch

Here is what I do: I use Permatex Rust Treatment--it comes in a rattle can--you spray it on and wire brush it into the rusty area until the area turns black. At that point you know the rust has been neutralized. Then I let it cure for a day, and spray Rustoleum Rusty Metal primer on and then I topcoat it.

Now I've also used Rusty Metal Primer by itself on rusty steel and left it outside for years and it doesn't rust through that primer--which is unusual. All other primer's are so porous that they rust through if left uncoated, but not Rusty Metal Primer. It is very tough stuff.

DIESELWRKS

I do something of the same put a rust stopping paint on it. also after that I have used a type of undercoating from napa I like it is paintable. but its black this is water proofing, i will put it on inner fenders inside of bumpers etc. even the parts of the springs the differential on top. then when spring comes pressure wash have a 2900 psi will take this back off if needed. then redo for the next 6months. its just simple upkeep doesn't cost to much just dont spay the under coating on the down pipe dont ask how I know.

sheriffav8r

I use a fairly cheap rust neutralizer from Lowes or HD. You paint it on and it turns the rust to iron oxide. Best stuff I've seen so far if you want to actually stop the rust and provide a protective coat on it. Either Jasco Prep and Primer or Klean Strip Rust Inhibitor. Or something along those lines. Just check the label and make sure it turns into a hard black paintable surface (that's the iron oxide). There are sprays too, but they are a lot more expensive for what you get. You can do your whole underside for about $20 with this paint on stuff. If you keep up with it yearly it doesn't need to be painted and makes the underside of your truck nice and clean looking....

BigErksG2

I used a blue and white can (Forget the name) that was a rust neutralizer and then you wait 24 hours and paint over it. I did what the directions said and it rusted through in less than a year. Im contemplating wire brushing the loose stuff and brushing gear oil on the underside if no other viable options come up soon.

Sherrifav8r - Iron oxide is rust but the neutralizers react with the iron oxide to make a paintable surface. I have had a bad long term experience with these products and am doing it again this year with something different, just not sure what.

Blueboy

I used a air grinder with wire brush to clean frame.
I painted with Por-15 then painted over that with
rustoleum. Use old clothing, gloves, and a hat
when painting with Por-15. This stuff does not
come off, if you get it on you.

gorms

POR-15 does work, I live in New England and my friend is a mechanic by trade, all of his vehicles get a coat of it before winter after cleaning/prep and they have all held up pretty good. It's not cheap, but 2 years ago my truck looked pretty good after the 5 cans of rustoleum every year, but salt has caught up. His under carriages still look rust free for the most part, and no spraying/scraping every year.

Robert Rausch

Salt is a killer on cars. First of all it attracts moisture--think of how salt in a salt shaker absorbs moisture and then hardens. Second of all salt is an oxidizing agent, and what is rust?--it's Iron Oxide. So salt is sort of double-trouble on cars--it holds moisture and it helps steel rust.

five20too

Well after reading all of your posts I decided to go with POR 15. I just placed an order for the 3-step system. I will report back with results after I get it finished. Thanks for all of your replies.

dkenny

sheriffav8r,
what about applying using a hand held spray gun. like the ones use for windex?

I bought a bottle, from the place you mentioned, for just this purpose..but a brush its going to take a while.

-dkenny

Junk Man

I drive old Datsun Z cars which have unibodies and are rust prone. Be sure to follow the POR directions exactly. The stuff works. I buy in the small cans so I don't have to open the big can for a little project. Wear gloves unless your hands need rust proofing. The stuff takes a week to get off skin.

five20too

I will and thanks for the info. I bought the 6 small cans so I don't have a lot to go bad at once. Dkenny I plan on using the spray bottle for the cleaner and etcher but I am going to try and paint on the actual sealant as much as I can. I may have to use the spray bottle for those hard to reach places though.